Which teratogen is strongly associated with neural tube defects, and what preventive measure reduces risk?

Which teratogen is strongly associated with neural tube defects, and what preventive measure reduces risk?

• A. Valproic acid; folate supplementation reduces risk
• B. Alcohol; folate supplementation
• C. Thalidomide; iron supplementation
• D. Tetracycline; calcium

Answer: (A)

Neural tube defects happen when the neural tube fails to close early in embryonic development, and folate status around conception is crucial for that closure process. Valproic acid, a commonly used anticonvulsant, is strongly associated with neural tube defects when exposure occurs in early pregnancy because it disrupts folate metabolism and neural tube formation. Folate supplementation before conception and during early pregnancy provides the needed substrates for DNA synthesis and methylation, helping the neural tube close properly. That’s why folate reduces the risk of these defects, and higher-dose folate is often recommended for women on antiseizure medications. The other agents have different risk profiles or don't have the same preventive role with neural tube defects. Thalidomide is famous for limb defects, while iron or calcium supplements don’t specifically prevent neural tube defects. Alcohol is teratogenic as well, but the strongest established link to neural tube defects is with valproic acid.

Neural tube defects happen when the neural tube fails to close early in embryonic development, and folate status around conception is crucial for that closure process. Valproic acid, a commonly used anticonvulsant, is strongly associated with neural tube defects when exposure occurs in early pregnancy because it disrupts folate metabolism and neural tube formation. Folate supplementation before conception and during early pregnancy provides the needed substrates for DNA synthesis and methylation, helping the neural tube close properly. That’s why folate reduces the risk of these defects, and higher-dose folate is often recommended for women on antiseizure medications.

The other agents have different risk profiles or don't have the same preventive role with neural tube defects. Thalidomide is famous for limb defects, while iron or calcium supplements don’t specifically prevent neural tube defects. Alcohol is teratogenic as well, but the strongest established link to neural tube defects is with valproic acid.